I had been in Mexico for a week when I found myself walking alone along a motorway at dusk. It was my first time in the country. There were the stray dogs, starving and friendly. The mountains rising high and blue in the distance.

A decade has passed since that evening in early February, so I can’t remember exactly what happened. What follows is most likely fiction as well as fact.

A car slowed down and a man leant his head out the window. “Güerita,” he shouted at me. “Are you crazy?” Güerita means fair-haired or fair-skinned girl.

I continued walking, while he drove slowly alongside me, listing in Spanish all the dangers that could befall a güerita alone on a motorway in Mexico at dusk. He kept shouting, “Aren’t you scared? Aren’t you scared?”

He was listening to Café Tacuba very loud in the car, a Mexican rock band who had made a comeback that year, 2004.

“How old are you?” he asked me.

“Nineteen.”

“You are in fact crazy,” he said, when I accepted his offer of a ride home. I got in his car. I trusted him.

He said that his name was Jesus. He was 22, a medical student. By the time he dropped me home, it was dark. He asked me whether I knew it was St Valentine’s Day very soon.

André Breton wrote that Mexico is a naturally surreal country. This observation may be dismissed as that of a Westerner in love with the “exotic”. Perhaps all foreign countries appear surreal to those from elsewhere. In any case, I immediately felt at home.

Frida Kahlo and her husband, Diego Rivera (Everett Collection/Alamy)On St Valentine’s Day, Jesus picked me up from the school where I was teaching English. It had a high yellow gate, guarded by a man with a lazy eye and a gun. Jesus handed me an origami “sea dog”, which he had made himself. I had never heard of a sea dog before, but I said thank you.

Then we drove at speed to a restaurant, where we talked about the mountain range on the road north to Mexico City. One part was called La Mujer Dormida (The Sleeping Woman) because the shape of the mountains from afar looked like the silhouette of a woman lying on her back.

“She is at rest,” Jesus said, “with her lover. What happened was this: they fell in love. She was called Iztaccihuatl and he was called Popocatepetl. He had to go and fight in a war. Iztaccihuatl’s father assumed he would not survive so he forced his daughter to marry another suitor. She was in despair and so she stabbed herself.” He paused. “Yes, that’s right – she stabbed herself.” I waited for him to go on.

“Then Popocatepetl did come back alive. He was in despair because she had died. So he carried her body up to the top of the freezing mountain because he hoped the cold might wake her up. But no. She did not wake up. Instead, she froze. So he lay down beside her and the snow covered them. They became the mountains.” Jesus put another forkful of tostada in his mouth. “That was the end of the story.”

“One of the most notable traits of the Mexican’s character is his willingness to contemplate horror,” the Mexican poet Octavio Paz wrote in his brilliant book on Mexican culture The Labyrinth of Solitude, published in 1950. “Our cult of death is also a cult of life, in the same way that love is a hunger for life and a longing for death. Our fondness for destruction derives not only from our masochistic tendencies but also from a certain variety of religious emotion.”

Paz won the Nobel Prize in literature in 1990, but he was criticised for portraying an abstract Mexican soul, as though there were only one, and not millions. But this misses his point – the book is a work of poetry, not sociology. It was written with great love for his own country, and great sadness. I read the book for the first time on that trip, and I have reread it many times since. Paz wrote, “Self-discovery is above all the realisation that we are alone.”

After dinner, Jesus and I sat in the cinema, eating chopped-up fruit covered with chilli powder and salt. We were watching The Passion of the Christ, starring Jim Caviezel as Jesus Christ, who was being nailed to a cross and hoisted into the air. The entire film was in Aramaic and Latin, with Spanish subtitles. Whole families had come to see it, not so much as entertainment, but religious duty. I went outside to smoke.

Then we drove to a bar. There was a Mexican pop song playing on the radio: a woman lamenting the countless roads that she would have to travel until she found her way back to her lover. Because it was St Valentine’s Day, the bar had been adorned with red heart-shaped balloons. Lovers sat absorbed in one another.

“What do you want?” asked the woman behind the bar. Jesus ordered us each a piña loca: a cocktail of tequila, pineapple juice, cream, and eggnog. They arrived in cups the size of buckets. I said that eggnog is rarely drunk in England. Maybe they drank it at Christmas in America?

The woman said, “Mexico: so far from God, so close to the United States.” She spoke English with an American accent, though she said she came from Veracruz, on the east coast of Mexico, where the shrimp cocktail was excellent. She asked me if I had been there. I said no.

Would I like to go there? Yes. She said that she had lived for many years in Miami, where she had started a successful dry-cleaning business. Her brother was still there. But she had missed Mexico, and come home. “Here the word is aguantar,” she told me. “To endure. In other words, to wait. To hope that things will get better.”

The inequality in this provincial city was brutal: the rich lived in palatial houses with statues of horses. They had pale skin, like the actors in the hugely popular telenovelas (soap operas), and indigenous maids.

The poor were mostly indigenous: they picked fruit from trees for low wages and fell out of the trees and died of their injuries. They rode in the bright green Volkswagen public buses, with good-luck charms swinging from the rear-view mirrors, as though the simple act of getting to and from work required benevolence from the gods.

But all the myths, including that of The Sleeping Woman, belonged to them; it was their land first. “Ahorita is another word,” the woman said. “It means ‘little now’, but really it means not now, but a bit later, or maybe never.” She rested her head on her hand.

“Let’s go,” I told Jesus, after the second piña loca. I had spent hours in the sun that day and the room was starting to spin. “Ahorita,” he said. I stood up, and swayed. “We have to go now,” I said. Jesus drove me home along the motorway at speed. I looked out the window and saw a shrine with flowers and the Virgen de Guadalupe, marking the spot where an accident had happened.

Zoe Pilger, who was drawn to Mexico at the age of 19“In a certain sense the history of Mexico, like that of every Mexican, is a struggle between the forms and formulas that have been imposed upon us and the explosions with which our individuality avenges itself,” Paz wrote. This surely is true of many peoples, and many places.

It was about a week after that St Valentine’s Day when I found myself sitting on a bench in the zocalo, the main square, watching people pass. I had finished teaching my classes for the day. A mariachi in smart black and gold approached me and asked if I would like to choose a song for him to sing.

I asked him for the only mariachi song that I knew, “Paloma Negra” (Black Dove). His voice rose with an emotion so naked that I was taken aback. He sang of a lover’s despair as his eyes “die” without looking into the eyes of his lover. The song is full of paradox. “Y aunque te amo con locura, ya no vuelvas.” (“And though I love you madly, don’t come back to me.”)

I had first heard “Paloma Negra” when I went to see the biopic of Frida Kahlo, released in cinemas two years before. It was included on the soundtrack, sung by the elderly and magnificent Chavela Vargas, who was herself rumoured to have had an affair with Kahlo in the 1930s. That film is a travesty, however: spoken in English, with Spanish accents.

The paintings of Frida Kahlo had been my entry into Mexican culture. As a teenager, I was obsessed. In Unos Cuantos Piquetitos! (A Few Small Nips!) (1935), a naked woman lies bloodied and dead on a bed, while a man stands over her, fully clothed, with a knife in his hand.#

Kahlo was inspired by an article that she had read in the newspaper about a man who had stabbed his wife many times. He had told the judge that it was “just a few small nips!” Kahlo made the work as a symbol of her own suffering following her husband Diego Rivera’s affair with her sister, Cristina.

After the painting was finished, she stuck a small bamboo birdcage to the canvas. It appeared to imprison the white dove painted beneath. Only the black dove, symbol of darkness, goes free.

In Mexico the shadow is not denied, but welcomed (AFP/Getty)What so enthralled me about Mexican culture was the way it celebrates darkness as an essential part of life. The shadow is not denied, but welcomed. “Since we cannot or dare not confront our own selves,” Paz wrote, “we resort to the fiesta. It fires us into the void; it is a drunken rapture that burns itself out, a pistol shot into the air, a sky rocket.”

Jesus and I remained friends after that St Valentine’s Day, but then we lost touch.

I didn’t return to Mexico until last November, when I went to stay on a near-empty island with only sand roads and a lot of flamingos. I was researching my second novel, which is partly set there. The island is called Black Hole or Black Head in Mayan.

When the Spanish arrived on the island in the 16th century, they decapitated their black slaves and stuck their heads on spears along the beach as a warning to the indigenous population to be obedient. This is what a man called Juan told me as soon as I got off the boat from the mainland. He was carving a sculpture of a mermaid out of a long tree trunk. He said that here the Spanish are not called conquistadores (conquerors), but piratas(pirates).

I went to a café near the beach, where an elderly woman called Rosie served me the best fish soup I have ever eaten. It was blood red and full of lobster. A young couple were at the next table. We started talking. They said they were from Mexico City and worked in business.

They asked me, “Aren’t you scared?” “Scared?” I said. “No, why?” They explained that the drug wars had been waging since I was last in Mexico and I was vulnerable as a woman on my own. I hadn’t been scared at all until they asked me if I was scared.

That night, an electrical storm made all the doors in my hotel bang on their hinges. The lizards slithered on to the balcony, and the jungle seemed to get closer and closer. The wind was screaming along the beach. Then the thunder stopped, and the rain stopped. It was silent. Paz wrote, “Silence – the prehistoric silence, stronger than all the pyramids and sacrifices, all the churches and uprisings and popular songs – comes back to rule over Mexico.”